Compressing text using AI by sending only prediction rank of next word
If you have a fixed predictor, then yes. If the predictor is not fixed but deterministic, the feasibility depends on the effort needed to update the predictor, and ensuring that messages include a time stamp to ensure the correct version of the predictor is used for compression and inflation.
You get a really nice property if the prediction order is in order of probability that the word occurs, and if you use fewer bits for lower numbers. You would get something that is pretty close to Shannon coding, which is not optimal but is still valid.